With regular copies selling for $80 minimum, and other variants breaking into three figures, Force of Will is the best thing you can open in a Secrets of Strixhaven play booster
Kitsa has vigilance, prowess, and two abilities - you can tap the otter to draw a card and then discard a card, or you can spend two generic mana and tap it to copy an instant or sorcery spell you control, with the caveat that Kitsa needs three power to do so
This was the card I sideboarded out the most throughout the tournament
First, Walking Ballista needs to have at least two +1/+1 counters on it (by paying four generic to cast it, ideally), and Heliod, the Sun-Crowned needs to be on the battlefield
Some third party organisations hosting Magic tournaments permit participants to include a set number of proxy cards in their decks (5 and 10 being common amounts), a clause that especially comes up for the cost-intensive vintage format
1 Flicker of Fate